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Semrau JD, DiSpirito AA. Methanobactin: A Novel Copper-Binding Compound Produced by Methanotrophs. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/978-3-030-23261-0_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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2
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E. Bjorck C, D. Dobson P, Pandhal J. Biotechnological conversion of methane to methanol: evaluation of progress and potential. AIMS BIOENGINEERING 2018. [DOI: 10.3934/bioeng.2018.1.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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3
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Ross MO, Rosenzweig AC. A tale of two methane monooxygenases. J Biol Inorg Chem 2017; 22:307-319. [PMID: 27878395 PMCID: PMC5352483 DOI: 10.1007/s00775-016-1419-y] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 11/15/2016] [Indexed: 11/24/2022]
Abstract
Methane monooxygenase (MMO) enzymes activate O2 for oxidation of methane. Two distinct MMOs exist in nature, a soluble form that uses a diiron active site (sMMO) and a membrane-bound form with a catalytic copper center (pMMO). Understanding the reaction mechanisms of these enzymes is of fundamental importance to biologists and chemists, and is also relevant to the development of new biocatalysts. The sMMO catalytic cycle has been elucidated in detail, including O2 activation intermediates and the nature of the methane-oxidizing species. By contrast, many aspects of pMMO catalysis remain unclear, most notably the nuclearity and molecular details of the copper active site. Here, we review the current state of knowledge for both enzymes, and consider pMMO O2 activation intermediates suggested by computational and synthetic studies in the context of existing biochemical data. Further work is needed on all fronts, with the ultimate goal of understanding how these two remarkable enzymes catalyze a reaction not readily achieved by any other metalloenzyme or biomimetic compound.
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Affiliation(s)
- Matthew O Ross
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Amy C Rosenzweig
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
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DiSpirito AA, Semrau JD, Murrell JC, Gallagher WH, Dennison C, Vuilleumier S. Methanobactin and the Link between Copper and Bacterial Methane Oxidation. Microbiol Mol Biol Rev 2016; 80:387-409. [PMID: 26984926 PMCID: PMC4867365 DOI: 10.1128/mmbr.00058-15] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Methanobactins (mbs) are low-molecular-mass (<1,200 Da) copper-binding peptides, or chalkophores, produced by many methane-oxidizing bacteria (methanotrophs). These molecules exhibit similarities to certain iron-binding siderophores but are expressed and secreted in response to copper limitation. Structurally, mbs are characterized by a pair of heterocyclic rings with associated thioamide groups that form the copper coordination site. One of the rings is always an oxazolone and the second ring an oxazolone, an imidazolone, or a pyrazinedione moiety. The mb molecule originates from a peptide precursor that undergoes a series of posttranslational modifications, including (i) ring formation, (ii) cleavage of a leader peptide sequence, and (iii) in some cases, addition of a sulfate group. Functionally, mbs represent the extracellular component of a copper acquisition system. Consistent with this role in copper acquisition, mbs have a high affinity for copper ions. Following binding, mbs rapidly reduce Cu(2+) to Cu(1+). In addition to binding copper, mbs will bind most transition metals and near-transition metals and protect the host methanotroph as well as other bacteria from toxic metals. Several other physiological functions have been assigned to mbs, based primarily on their redox and metal-binding properties. In this review, we examine the current state of knowledge of this novel type of metal-binding peptide. We also explore its potential applications, how mbs may alter the bioavailability of multiple metals, and the many roles mbs may play in the physiology of methanotrophs.
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Affiliation(s)
- Alan A DiSpirito
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Jeremy D Semrau
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - J Colin Murrell
- Earth and Life Systems Alliance, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
| | - Warren H Gallagher
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, USA
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Stéphane Vuilleumier
- Department of Microbiology, Genomics and the Environment, UMR 7156 UNISTRA-CNRS, Université de Strasbourg, Strasbourg, France
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5
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Abstract
Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, protein-protein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.
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Affiliation(s)
- Sarah Sirajuddin
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Amy C. Rosenzweig
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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Sazinsky MH, Lippard SJ. Methane Monooxygenase: Functionalizing Methane at Iron and Copper. Met Ions Life Sci 2015; 15:205-56. [DOI: 10.1007/978-3-319-12415-5_6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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7
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Culpepper MA, Rosenzweig AC. Structure and protein-protein interactions of methanol dehydrogenase from Methylococcus capsulatus (Bath). Biochemistry 2014; 53:6211-9. [PMID: 25185034 PMCID: PMC4188263 DOI: 10.1021/bi500850j] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
![]()
In
the initial steps of their metabolic pathway, methanotrophic
bacteria oxidize methane to methanol with methane monooxygenases (MMOs)
and methanol to formaldehyde with methanol dehydrogenases (MDHs).
Several lines of evidence suggest that the membrane-bound or particulate
MMO (pMMO) and MDH interact to form a metabolic supercomplex. To further
investigate the possible existence of such a supercomplex, native
MDH from Methylococcus capsulatus (Bath) has been
purified and characterized by size exclusion chromatography with multi-angle
light scattering and X-ray crystallography. M. capsulatus (Bath) MDH is primarily a dimer in solution, although an oligomeric
species with a molecular mass of ∼450–560 kDa forms
at higher protein concentrations. The 2.57 Å resolution crystal
structure reveals an overall fold and α2β2 dimeric architecture similar to those of other MDH structures.
In addition, biolayer interferometry studies demonstrate specific
protein–protein interactions between MDH and M. capsulatus (Bath) pMMO as well as between MDH and the truncated recombinant
periplasmic domains of M. capsulatus (Bath) pMMO
(spmoB). These interactions exhibit KD values of 833 ± 409 nM and 9.0 ± 7.7 μM, respectively.
The biochemical data combined with analysis of the crystal lattice
interactions observed in the MDH structure suggest a model in which
MDH and pMMO associate not as a discrete, stoichiometric complex but
as a larger assembly scaffolded by the intracytoplasmic membranes.
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Affiliation(s)
- Megen A Culpepper
- Departments of Molecular Biosciences and Chemistry, Northwestern University , Evanston, Illinois 60208, United States
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8
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Yao S, Herwig C, Xiong Y, Company A, Bill E, Limberg C, Driess M. Monooxygenase-Like Reactivity of an Unprecedented Heterobimetallic {FeO2Ni} Moiety. Angew Chem Int Ed Engl 2010; 49:7054-8. [DOI: 10.1002/anie.201001914] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Yao S, Herwig C, Xiong Y, Company A, Bill E, Limberg C, Driess M. Monooxygenase-Like Reactivity of an Unprecedented Heterobimetallic {FeO2Ni} Moiety. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201001914] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Patel RN, Hou CT, Laskin AI, Felix A. Microbial Oxidation of Hydrocarbons: Properties of a Soluble Methane Monooxygenase from a Facultative Methane-Utilizing Organism, Methylobacterium sp. Strain CRL-26. Appl Environ Microbiol 2010; 44:1130-7. [PMID: 16346133 PMCID: PMC242158 DOI: 10.1128/aem.44.5.1130-1137.1982] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methylobacterium sp. strain CRL-26 grown in a fermentor contained methane monooxygenase activity in soluble fractions. Soluble methane monooxygenase catalyzed the epoxidation/hydroxylation of a variety of hydrocarbons, including terminal alkenes, internal alkenes, substituted alkenes, branched-chain alkenes, alkanes (C(1) to C(8)), substituted alkanes, branched-chain alkanes, carbon monoxide, ethers, and cyclic and aromatic compounds. The optimum pH and temperature for the epoxidation of propylene by soluble methane monooxygenase were found to be 7.0 and 40 degrees C, respectively. Among various compounds tested, only NADH(2) or NADPH(2) could act as an electron donor. Formate and NAD (in the presence of formate dehydrogenase contained in the soluble fraction) or 2-butanol in the presence of NAD and secondary alcohol dehydrogenase generated the NADH(2) required for the methane monooxygenase. Epoxidation of propylene catalyzed by methane monooxygenase was not inhibited by a range of potential inhibitors, including metal-chelating compounds and potassium cyanide. Sulfhydryl agents and acriflavin inhibited monooxygenase activity. Soluble methane monooxygenase was resolved into three components by ion-exchange chromatography. All three compounds are required for the epoxidation and hydroxylation reactions.
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Affiliation(s)
- R N Patel
- Corporate Research Science Laboratory, Exxon Research and Engineering Company, Linden, New Jersey 07036
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11
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Phelps PA, Agarwal SK, Speitel GE, Georgiou G. Methylosinus trichosporium OB3b Mutants Having Constitutive Expression of Soluble Methane Monooxygenase in the Presence of High Levels of Copper. Appl Environ Microbiol 2010; 58:3701-8. [PMID: 16348810 PMCID: PMC183163 DOI: 10.1128/aem.58.11.3701-3708.1992] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The methanotrophic bacterium Methylosinus trichosporium OB3b is unusually active in degrading recalcitrant haloalkanes such as trichloroethylene (TCE). The first and rate-limiting step in the degradation of TCE is catalyzed by a soluble methane monooxygenase (sMMO). This enzyme is not expressed when the cells are grown in the presence of copper at concentrations typically found in polluted groundwater. Under these conditions, M. trichosporium OB3b expresses a particulate form of the enzyme (pMMO), which has a narrow substrate specificity and does not degrade TCE at any significant rate. We have isolated M. trichosporium OB3b mutants that are deficient in pMMO and express sMMO constitutively in the presence of elevated concentrations of copper. One mutant (PP358) exhibited a TCE degradation rate which was almost twice as high as that of the wild-type strain grown under optimal conditions (without copper). All of the mutants lost the ability to express pMMO activity and to form stacked intracellular membranes characteristic of wild-type cells expressing pMMO.
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Affiliation(s)
- P A Phelps
- Department of Chemical Engineering and Department of Civil Engineering, University of Texas, Austin, Texas 78712
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12
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Topp E, Knowles R. Effects of Nitrapyrin [2-Chloro-6-(Trichloromethyl) Pyridine] on the Obligate Methanotroph Methylosinus trichosporium OB3b. Appl Environ Microbiol 2010; 47:258-62. [PMID: 16346465 PMCID: PMC239655 DOI: 10.1128/aem.47.2.258-262.1984] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrapyrin inhibited growth, CH(4) oxidation, and NH(4) oxidation, but not the oxidation of CH(3)OH, HCHO, or HCOONa, by Methylosinus trichosporium OB3b, suggesting that nitrapyrin acts against the methane monooxygenase enzyme system. The inhibition of CH(4) oxidation could be reversed by repeated washing of nitrapyrin-inhibited cells, indicating that its effect is bacteriostatic. The addition of Cu did not release the inhibition. Methane oxidation was also inhibited by 6-chloro-2-picoline. These data suggest that the mode of action of nitrapyrin on M. trichosporium is different from that on chemoautotrophic NH(4) oxidizers or methanogens.
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Affiliation(s)
- E Topp
- Department of Microbiology, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec H9X 1C0, Canada
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13
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Siewert I, Limberg C. Low-Molecular-Weight Analogues of the Soluble Methane Monooxygenase (sMMO): From the Structural Mimicking of Resting States and Intermediates to Functional Models. Chemistry 2009; 15:10316-28. [DOI: 10.1002/chem.200901910] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Babel W, Steudel A. Cytochromspektren methylotropher Bakterien. J Basic Microbiol 2007. [DOI: 10.1002/jobm.19770170403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Myronova N, Kitmitto A, Collins RF, Miyaji A, Dalton H. Three-Dimensional Structure Determination of a Protein Supercomplex That Oxidizes Methane to Formaldehyde in Methylococcus capsulatus (Bath). Biochemistry 2006; 45:11905-14. [PMID: 17002291 DOI: 10.1021/bi061294p] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of methane to methanol in methanotrophs is catalyzed by the enzyme methane monooxygenase (MMO). Two distinct forms of this enzyme exist, a soluble cytoplasmic MMO (sMMO) and a membrane-bound particulate form (pMMO). The active protein complex termed pMMO-C was purified recently from Methylococcus capsulatus (Bath). The complex consists of pMMO hydroxylase and an additional component pMMO-R, which was proposed to be the reductase for the pMMO complex. Further study of this complex has led here to the proposal that the pMMO-R is in fact methanol dehydrogenase, the subsequent enzyme in the methane oxidation pathway by methanotrophs. We describe here the biochemical and biophysical characterization of a stable purified complex of pMMO hydroxylase (pMMO-H) with methanol dehydrogenase (MDH) and report the first three-dimensional (3D) structure, determined by cryoelectron microscopy and single particle analysis to approximately 16 A resolution. The 3D structure reported here provides the first insights into the supramolecular organization of pMMO with MDH. These studies of pMMO-MDH complexes have provided further understanding of the structural basis for the particular functions of the enzymes in this system which might also be of relevance to the complete process of methane oxidation by methanotrophs under high copper concentration in the environment.
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Affiliation(s)
- Natalia Myronova
- Department of Biological Sciences, University of Warwick, Coventry CV4 8EZ, UK
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Basu P, Katterle B, Andersson KK, Dalton H. The membrane-associated form of methane mono-oxygenase from Methylococcus capsulatus (Bath) is a copper/iron protein. Biochem J 2003; 369:417-27. [PMID: 12379148 PMCID: PMC1223091 DOI: 10.1042/bj20020823] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2002] [Revised: 09/16/2002] [Accepted: 10/14/2002] [Indexed: 11/17/2022]
Abstract
A protocol has been developed which permits the purification of a membrane-associated methane-oxidizing complex from Methylococcus capsulatus (Bath). This complex has approximately 5 fold higher specific activity than any purified particulate methane mono-oxygenase (pMMO) previously reported from M. capsulatus (Bath). This efficiently functioning methane-oxidizing complex consists of the pMMO hydroxylase (pMMOH) and an unidentified component we have assigned as a potential pMMO reductase (pMMOR). The complex was isolated by solubilizing intracytoplasmic membrane preparations containing the high yields of active membrane-bound pMMO (pMMO(m)), using the non-ionic detergent dodecyl-beta-D-maltoside, to yield solubilized enzyme (pMMO(s)). Further purification gave rise to an active complex (pMMO(c)) that could be resolved (at low levels) by ion-exchange chromatography into two components, the pMMOH (47, 27 and 24 kDa subunits) and the pMMOR (63 and 8 kDa subunits). The purified complex contains two copper atoms and one non-haem iron atom/mol of enzyme. EPR spectra of preparations grown with (63)Cu indicated that the copper ion interacted with three or four nitrogenic ligands. These EPR data, in conjunction with other experimental results, including the oxidation by ferricyanide, EDTA treatment to remove copper and re-addition of copper to the depleted protein, verified the essential role of copper in enzyme catalysis and indicated the implausibility of copper existing as a trinuclear cluster. The EPR measurements also demonstrated the presence of a tightly bound mononuclear Fe(3+) ion in an octahedral environment that may well be exchange-coupled to another paramagnetic species.
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Affiliation(s)
- Piku Basu
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, U.K
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18
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Takeguchi M, Furuto T, Sugimori D, Okura I. Optimization of methanol biosynthesis byMethylosinus trichosporium OB3b: An approach to improve methanol accumulation. Appl Biochem Biotechnol 1997. [DOI: 10.1007/bf02785987] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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Cook SA, Shiemke AK. Evidence that copper is a required cofactor for the membrane-bound form of methane monooxygenase. J Inorg Biochem 1996. [DOI: 10.1016/0162-0134(95)00239-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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Dikjhuizen L, Sokolov IG. Regulation of oxidation and assimilation of one-carbon compounds in methylotrophic bacteria. BIOTECHNOLOGY (READING, MASS.) 1991; 18:127-48. [PMID: 1909911 DOI: 10.1016/b978-0-7506-9188-8.50013-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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21
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Smith DD, Dalton H. Solubilisation of methane monooxygenase from Methylococcus capsulatus (Bath). EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 182:667-71. [PMID: 2502395 DOI: 10.1111/j.1432-1033.1989.tb14877.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The membrane-bound (particulate) form of methane monooxygenase from Methylococcus capsulatus (Bath) has been solubilised using the non-ionic detergent dodecyl-beta-D-maltoside. A wide variety of detergents were tested and found to solubilise membrane proteins but did not yield methane monooxygenase in a form that could be subsequently activated. After solubilisation with dodecyl-beta-D-maltoside, enzyme activity was recovered using either egg or soya-bean lipids. Attempts to further purify the solubilized methane monooxygenaser protein into its component polypeptides were unsuccessful and resulted in complete loss of enzyme activity. The major polypeptides present in the solubilised enzyme had molecular masses of 49 kDa, 23 kDa and 22 kDa which were similar to those seen in crude extracts [Prior, S. D. & Dalton H. (1985) J. Gen. Microbiol. 131, 155-163]. Studies on substrate and inhibitor specificities indicated that the membrane-associated and solubilised forms of methane monooxygenase were quite similar to each other but differed substantially from the well-characterised soluble methane monooxygenase found in cells grown in a low copper regime and synthesised independently of the particulate methane monooxygenase.
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Affiliation(s)
- D D Smith
- Department of Biological Sciences, University of Warwick, Coventry, UK
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22
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Frank J, Dijkstra M, Balny C, Verwiel PE, Duine JA. Methanol dehydrogenase: mechanism of action. Antonie Van Leeuwenhoek 1989; 56:25-34. [PMID: 2673028 DOI: 10.1007/bf00822581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- J Frank
- Dept. of Microbiol. & Enzymol., Delft University of Technology, The Netherlands
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Abstract
Enzymatic systems employed by microorganisms for oxidative transformation of various organic molecules include laccases, ligninases, tyrosinases, monooxygenases, and dioxygenases. Reactions performed by these enzymes play a significant role in maintaining the global carbon cycle through either transformation or complete mineralization of organic molecules. Additionally, oxidative enzymes are instrumental in modification or degradation of the ever-increasing man-made chemicals constantly released into our environment. Due to their inherent stereo- and regioselectivity and high efficiency, oxidative enzymes have attracted attention as potential biocatalysts for various biotechnological processes. Successful commercial application of these enzymes will be possible through employing new methodologies, such as use of organic solvents in the reaction mixtures, immobilization of either the intact microorganisms or isolated enzyme preparations on various supports, and genetic engineering technology.
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Affiliation(s)
- F S Sariaslani
- Central Research and Development Department, E.I. Du Pont de Nemours and Company, Wilmington, Delaware
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Use of “Specific” Inhibitors in Biogeochemistry and Microbial Ecology. ADVANCES IN MICROBIAL ECOLOGY 1988. [DOI: 10.1007/978-1-4684-5409-3_8] [Citation(s) in RCA: 334] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Patel RN, Savas JC. Purification and properties of the hydroxylase component of methane monooxygenase. J Bacteriol 1987; 169:2313-7. [PMID: 3106336 PMCID: PMC212168 DOI: 10.1128/jb.169.5.2313-2317.1987] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Methane monooxygenase from Methylobacterium sp. strain CRL-26 which catalyzes the oxygenation of hydrocarbons was resolved into two components, a hydroxylase and a flavoprotein. An anaerobic procedure was developed for the purification of the hydroxylase to homogeneity. The molecular weight of the hydroxylase as determined by gel filtration was 220,000, and that determined by sedimentation equilibrium analysis was about 225,000. The purified hydroxylase contained three nonidentical subunits with molecular weights of about 55,000, 40,000, and 20,000, in equal amounts as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is an alpha 2 beta 2 gamma 2 protein. Optical absorption spectra revealed peaks near 408 and 280 nm, and fluorescence spectra revealed emission peaks at 490 and 630 nm. The purified hydroxylase contained 2.8 +/- 0.2 mol of iron and 0.5 +/- 0.1 mol of zinc per mol of protein but negligible amounts of acid-labile sulfide. The antisera prepared against the hydroxylase showed cross-reactivity with hydroxylase components in soluble extracts from other methanotrophs.
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27
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Nicolaidis AA, Sargent AW. Isolation of methane monooxygenase-deficient mutants fromMethylosinus trichosporiumOB3b using dichloromethane. FEMS Microbiol Lett 1987. [DOI: 10.1111/j.1574-6968.1987.tb02139.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Abstract
An anaerobic procedure was developed for the purification of the flavin:NADH oxidoreductase (flavoprotein) component of methane monooxygenase to homogeneity. The molecular weight of the flavoprotein determined by gel filtration was about 40,000, and by sedimentation equilibrium analysis, about 38,000. The purified flavoprotein is a monomeric protein with a sedimentation constant (S20,W) value of about 2.1 S. The absorption spectrum of the flavoprotein has a peak at 460 nm and shoulder at 395 nm. The fluorescent excitation and emission spectra of the fluorescent component of flavoprotein had peaks at 450, 370, and 530 nm, respectively. A FAD was identified as a prosthetic group of flavoprotein by thin-layer chromatography. The flavoprotein contained about 1 mol of FAD and 2 mol each of iron and acid-labile sulfide per mole of protein. The flavoprotein was directly reduced by NADH under anaerobic conditions. The formation of neutral flavin semiquinone was detected during anaerobic titration of flavoprotein by NADH and also as a free radical signal at a g value of 2.004 by EPR spectroscopy. The iron sulfur cluster has g values of 2.04, 1.96, and 1.87, yielding a g average of 1.96, characteristic of a Fe2S2 center. Antibody prepared against the flavoprotein reacted with flavoprotein and inhibited methane monooxygenase activity.
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Cornish A, MacDonald J, Burrows KJ, King TS, Scott D, Higgins IJ. Succinate as anin vitro electron donor for the particulate methane mono-oxygenase ofMethylosinus trichosporium OB3b. Biotechnol Lett 1985. [DOI: 10.1007/bf01030278] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lund J, Woodland MP, Dalton H. Electron transfer reactions in the soluble methane monooxygenase of Methylococcus capsulatus (Bath). EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 147:297-305. [PMID: 3918864 DOI: 10.1111/j.1432-1033.1985.tb08750.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Aerobic stopped-flow experiments have confirmed that component C is the methane monooxygenase component responsible for interaction with NADH. Reduction of component C by NADH is not the rate-limiting step for component C in the methane monooxygenase reaction. Removal and reconstitution of the redox centres of component C suggest a correlation between the presence of the FAD and Fe2S2 redox centres and NADH: acceptor reductase activity and methane monooxygenase activity respectively, consistent with the order of electron flow: NADH----FAD----Fe2S2----component A. This order suggests that component C functions as a 2e-1/1e-1 transformase, splitting electron pairs from NADH for transfer to component A via the one-electron-carrying Fe2S2 centre. Electron transfer has been demonstrated between the reductase component, component C and the oxygenase component, component A, of the methane monooxygenase complex from Methylococcus capsulatus (Bath) by three separate methods. This intermolecular electron transfer step is not rate-determining for the methane monooxygenase reaction. Intermolecular electron transfer was independent of component B, the third component of the methane monooxygenase. Component B is required to switch the oxidase activity of component A to methane mono-oxygenase activity, suggesting that the role of component B is to couple substrate oxidation to electron transfer, via the methane monooxygenase components.
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The methane mono-oxygenase reaction system studied in vivo by membrane-inlet mass spectrometry. Biochem J 1985; 225:441-8. [PMID: 2983676 PMCID: PMC1144609 DOI: 10.1042/bj2250441] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A membrane-inlet mass spectrometer connected to an open-system cuvette was used for direct measurement of dissolved methane and O2 in bacterial samples of strain OU-4-1, a type II methanotrophic bacterium. A technique was applied for keeping the concentration of dissolved methane or O2 in the sample constant while the concentration of the other dissolved gas was varied. This allowed the reaction mechanism of methane mono-oxygenase to be studied in vivo. The enzyme was found to follow a random bi-reactant mechanism with respect to binding of methane and O2. Binding of one substrate decreased the affinity for the other. The true binding constants were 1 microM for methane and 0.14 microM for O2. Studies of HCN inhibition confirmed the random bi-reactant mechanism. HCN was found to be a non-exclusive inhibitor with a binding constant of 0.4 microM.
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Copper stress underlies the fundamental change in intracellular location of methane mono-oxygenase in methane-oxidizing organisms: Studies in batch and continuous cultures. Biotechnol Lett 1983. [DOI: 10.1007/bf00132233] [Citation(s) in RCA: 182] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Ghisalba O, Heinzer F. Methanol from methane — a hypothetical microbial conversion compared with the chemical process. ACTA ACUST UNITED AC 1982. [DOI: 10.1007/bf01945078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Higgins IJ, Best DJ, Scott D. Generation of products by methanotrophs. BASIC LIFE SCIENCES 1982; 19:383-402. [PMID: 6802126 DOI: 10.1007/978-1-4684-4142-0_29] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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36
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37
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Meyers A. Evaluation of bromomethane as a suitable analogue in methane oxidation studies. FEMS Microbiol Lett 1980. [DOI: 10.1111/j.1574-6968.1980.tb05656.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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38
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O'Keeffe DT, Anthony C. The two cytochromes c in the facultative methylotroph Pseudomonas am1. Biochem J 1980; 192:411-9. [PMID: 6263253 PMCID: PMC1162355 DOI: 10.1042/bj1920411] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
It was previously suggested that there is only one soluble cytochrome c in Pseudomonas AM1, having a molecular weight of 20000, a redox midpoint potential of about +260mV and a low isoelectric pint [Anthony (1975) Biochem. J.146, 289-298; Widdowson & Anthony (1975) Biochem. J.152, 349-356]. A more thorough examination of the soluble fraction of methanol-grown Pseudomonas AM1 has now revealed the presence of two different cytochromes c. These were both purified to homogeneity by acid treatment, ion-exchange chromatography, gel filtration, chromatography on hydroxyapatite and preparative isoelectric focusing. Molecular weights were determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis; midpoint redox potentials were determined directly by using platinum and calomel electrodes; isoelectric points were estimated by electrophoresis and by the behaviour of the two cytochromes on ion-exchange celluloses. The more abundant cytochrome c(H) (lambda(max.) 550.5nm) had a low molecular weight (11000), a midpoint potential of about +294mV and a high isoelectric point, not being adsorbed on DEAE-cellulose in 20mm-Tris/HCl buffer, pH8.0. The less abundant cytochrome c(L) (lambda(max.) 549nm) was about 30% of the total; it had a high molecular weight (20900), a midpoint potential of about +256mV and a low isoelectric point, binding strongly to DEAE-cellulose in 20mm-Tris/HCl buffer, pH8.0. The pH-dependence of the midpoint redox potentials of the two cytochromes c were very similar. There were four ionizations affecting the redox potentials in the pH range studied (pH4.0-9.5), two in the oxidized form (pK values about 3.5 and 5.5) and two in the reduced form (pK values about 4.5 and 6.5), suggesting that the ionizing groups involved may be the two propionate side chains of the haem. Neither of the cytochromes c was present in mutant PCT76, which was unable to oxidize or grow on C(1) compounds, although still able to grow well on multicarbon compounds such as succinate. Whether or not these two cytochromes c have separate physiological functions is not yet certain.
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Hou CT, Patel RN, Laskin AI. Epoxidation and Ketone Formation by C1-Utilizing Microbes. ADVANCES IN APPLIED MICROBIOLOGY 1980. [DOI: 10.1016/s0065-2164(08)70329-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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40
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Stirling DI, Dalton H. Properties of the methane mono-oxygenase from extracts of Methylosinus trichosporium OB3b and evidence for its similarity to the enzyme from Methylococcus capsulatus (Bath). EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 96:205-12. [PMID: 572296 DOI: 10.1111/j.1432-1033.1979.tb13030.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
1. The methane mono-oxygenase from Methylosinus trichosporium OB3b was soluble. The only suitable electron donor was NAD(P)H, neither sodium L-ascorbate nor electrons derived from the oxidation of methanol could substitute for NAD(P)H. Evidence is presented for the existence of an NAD+-linked formaldehyde dehydrogenase. 2. Mono-oxygenase activity was not inhibited by a range of potential inhibitors including potassium cyanide, amytal, carbon monoxide or various metal-chelating agents, although 8-hydroxyquinoline and ethyne were effective in this respect. 3. Although the enzyme preparations were unstable on storage, the crude extract could be resolved into two components by ion-exchange chromatography. Activity could be restored to one of the components on addition of purified components from Methylococcus capsulatus (Bath). 4. Cross-reactivity of mono-oxygenase components and other similarities between the enzymes from M. trichosporium and M. capsulatus are discussed. The properties of the M. trichosporium methane mono-oxygenase reported here are contrasted with the properties of the same enzyme reported by others.
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Haubold R. Copper ions cause cell elongation of Methylocystis strains. ZEITSCHRIFT FUR ALLGEMEINE MIKROBIOLOGIE 1979; 19:759-62. [PMID: 121179 DOI: 10.1002/jobm.3630191012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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42
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Keat MJ, Hopper DJ. P-cresol and 3,5-xylenol methylhydroxylases in Pseudomonas putida N.C.I.B. 9896. Biochem J 1978; 175:649-58. [PMID: 743215 PMCID: PMC1186115 DOI: 10.1042/bj1750649] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pseudomonas putida N.C.I.B. 9869, when grown on 3,5-xylenol, hydroxylates the methyl groups on 3,5-xylenol and on p-cresol by two different enzymes. 3,5-Xylenol methylhydroxylase, studied only in relatively crude extracts, requires NADH, is not active with p-cresol and is inhibited by cyanide, but not by CO. The p-cresol methylhydroxylase requires an electron acceptor and will act under anaerobic conditions. It was purified and is a flavocytochrome c of mol.wt. approx. 114,000 consisting of two subunits of equal size. The enzyme catalyses the hydroxylation of p-cresol (Km 16 micron) and the further oxidation of product, p-hydroxybenzyl alcohol (Km 27 micron) to p-hydroxybenzaldehyde. A different p-cresol methylhydroxylase of the flavocytochrome c type is induced by growth on p-cresol. It too was purified and has mol.wt. approx. 100,000, and again consisted of two equal-size subunits. The Km for p=cresol 3.6 micron and for p=hydroxybenzyl alcohol, 15 micron.
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Bamforth CW, Quayle JR. Aerobic and anaerobic growth of Paracoccus denitrificans on methanol. Arch Microbiol 1978; 119:91-7. [PMID: 718372 DOI: 10.1007/bf00407934] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
1. The dye-linked methanol dehydrogenase from Paracoccus denitrificans grown aerobically on methanol has been purified and its properties compared with similar enzymes from other bacteria. It was shown to be specific and to have high affinity for primary alcohols and formaldehyde as substrate, ammonia was the best activator and the enzyme could be linked to reduction of phenazine methosulphate. 2. Paracoccus denitrificans could be grown anaerobically on methanol, using nitrate or nitrite as electron acceptor. The methanol dehydrogenase synthesized under these conditions could not be differentiated from the aerobically-synthesized enzyme. 3. Activities of methanol dehydrogenase, formaldehyde dehydrogenase, formate dehydrogenase, nitrate reductase and nitrite reductase were measured under aerobic and anaerobic growth conditions. 4. Difference spectra of reduced and oxidized cytochromes in membrane and supernatant fractions of methanol-grown P. denitrificans were measured. 5. From the results of the spectral and enzymatic analyses it has been suggested that anaerobic growth on methanol/nitrate is made possible by reduction of nitrate to nitrite using electrons derived from the pyridine nucleotide-linked dehydrogenations of formaldehyde and formate, the nitrite so produced then functioning as electron acceptor for methanol dehydrogenase via cytochrome c and nitrite reductase.
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Patt TE, Hanson RS. Intracytoplasmic membrane, phospholipid, and sterol content of Methylobacterium organophilum cells grown under different conditions. J Bacteriol 1978; 134:636-44. [PMID: 96093 PMCID: PMC222297 DOI: 10.1128/jb.134.2.636-644.1978] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intracytoplasmic membranes were present in Methylobacterium organophilum when cells were grown with methane, but not methanol or glucose, as the sole carbon and energy source. Cells grown with methane as the carbon and energy source and low levels of dissolved oxygen had the greatest amount of intracytoplasmic membrane. Cells grown with increased levels of dissolved oxygen had less intracytoplasmic membrane. The amount of total lipid correlated with the amount of membrane material observed in thin sections. The individual phospholipids varied in amount, but the same four were present in M. organophilum grown with different substrates and oxygen levels. Phosphatidyl choline was present as a major component of the phospholipids. Sterols were present, and they differed from those in the type I methylotroph Methylococcus capsulatus. The relative amounts of different sterols and squalene changed with the substrate provided for growth. The greatest amounts of sterols were found in methane-grown cells grown at low levels of dissolved oxygen. None of the unusual or usual membrane components assayed was uniquely present in the intracytoplasmic membranes.
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Stirling DI, Dalton H. Effect of metal-binding and other compounds on methane oxidation by two strains of Methylococcus capsulatus. Arch Microbiol 1977; 114:71-6. [PMID: 410382 DOI: 10.1007/bf00429633] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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46
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Babel W, Steudel A. [Cytochrome spectra of methylotrophic bacteria]. ZEITSCHRIFT FUR ALLGEMEINE MIKROBIOLOGIE 1977; 17:267-75. [PMID: 407733 DOI: 10.1002/jobm.3630170403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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47
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Suzuki I, Kwok SC, Dular U. Competitive inhibition of ammonia oxidation in Nitrosomonas europaea by methane, carbon monoxide or methanol. FEBS Lett 1976; 72:117-20. [PMID: 1001454 DOI: 10.1016/0014-5793(76)80825-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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48
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Abstract
Intact cells of Nitrosomonas europaea grown in an ammonium salts medium will oxidise ammonium ions, hydroxylamine and ascorbate-TMPD; there is no oxidation of carbon monoxide, methane or methanol. The Km value for ammonia oxidation is highly pH dependent with a minimum value of 0.5 mM above pH 8.0. This suggests that free ammonia is the species crossing the cytoplasmic membrane(s). The measurement of respiration driven proton translocation indicates that there is probably only one proton translocating loop (loop 3) association with hydroxylamine oxidation. The oxidation of "endogenous" substrates is sometimes associated with more than one proton-translocating loop. These results indicate that during growth hydroxylamine oxidation is probably associated with a maximum P/O ratio of 1.
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Colby J, Dalton H. Some properties of a soluble methane mono-oxygenase from Methylococcus capsulatus strain Bath. Biochem J 1976; 157:495-7. [PMID: 962879 PMCID: PMC1163879 DOI: 10.1042/bj1570495] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Soluble extracts of Methylococcus capsulatus (Bath), obtained by centrifugation of crude extracts at 160000g for 1h, catalyse the NAD(P)H- and O2-dependent disappearance of bromomethane, and also the formation of methanol from methane. Soluble methane mono-oxygenase is not inhibited by chelating agents or by most electron-transport inhibitors, and is a multicomponent enzyme.
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